From b43d1f9f7067c6759b1051e8ecb84e82cef569fe Mon Sep 17 00:00:00 2001 From: Mao Wenan Date: Mon, 9 Dec 2019 21:31:25 +0800 Subject: [PATCH] af_packet: set defaule value for tmo There is softlockup when using TPACKET_V3: ... NMI watchdog: BUG: soft lockup - CPU#2 stuck for 60010ms! (__irq_svc) from [] (_raw_spin_unlock_irqrestore+0x44/0x54) (_raw_spin_unlock_irqrestore) from [] (mod_timer+0x210/0x25c) (mod_timer) from [] (prb_retire_rx_blk_timer_expired+0x68/0x11c) (prb_retire_rx_blk_timer_expired) from [] (call_timer_fn+0x90/0x17c) (call_timer_fn) from [] (run_timer_softirq+0x2d4/0x2fc) (run_timer_softirq) from [] (__do_softirq+0x218/0x318) (__do_softirq) from [] (irq_exit+0x88/0xac) (irq_exit) from [] (msa_irq_exit+0x11c/0x1d4) (msa_irq_exit) from [] (handle_IPI+0x650/0x7f4) (handle_IPI) from [] (gic_handle_irq+0x108/0x118) (gic_handle_irq) from [] (__irq_usr+0x44/0x5c) ... If __ethtool_get_link_ksettings() is failed in prb_calc_retire_blk_tmo(), msec and tmo will be zero, so tov_in_jiffies is zero and the timer expire for retire_blk_timer is turn to mod_timer(&pkc->retire_blk_timer, jiffies + 0), which will trigger cpu usage of softirq is 100%. Fixes: f6fb8f100b80 ("af-packet: TPACKET_V3 flexible buffer implementation.") Tested-by: Xiao Jiangfeng Signed-off-by: Mao Wenan Signed-off-by: David S. Miller --- net/packet/af_packet.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/net/packet/af_packet.c b/net/packet/af_packet.c index 53c1d41fb1c9..118cd66b7516 100644 --- a/net/packet/af_packet.c +++ b/net/packet/af_packet.c @@ -544,7 +544,8 @@ static int prb_calc_retire_blk_tmo(struct packet_sock *po, msec = 1; div = ecmd.base.speed / 1000; } - } + } else + return DEFAULT_PRB_RETIRE_TOV; mbits = (blk_size_in_bytes * 8) / (1024 * 1024);